This invention relates to an axial bearing with a cage containing rolling elements in pockets, said cage located between two planar parallel races that are in particular made of sheet metal, wherein these three components are held together as a unit by opposing form-locked containment, and wherein both races transition into collars that surround the cage, with play, at an outer or inner peripheral edge.
A prior art axial roller bearing of this type is known from U.S. Pat. No. 2,891,828. It comprises two races that extend in planes parallel to one another, each of which transitions into an axial collar at the outer or inner peripheral edge. Bearing needles held in a cage roll between the two races on associated raceways. The two collars, which are axially opposed to one another, surround the cage, with play, and have a number of retaining projections at their ends that are evenly distributed along the perimeter. These retaining projections, which are directed either radially inwardly or radially outwardly, contain the cage, thus forming a lasting axial bearing unit that consists of two races and a cage. The oil flow occurs from the inside outward as a result of the rotating axial bearing.
There are areas of application in gear designs in which the oil stream is to be redirected in a definite direction after leaving the bearing. However, this is not possible using the prior art bearings in this class.
It is thus the object of this invention to further develop a bearing in this class such that the flow of lubricant is made to be as unhindered and as directed as possible.
According to the invention, this object is met in that the collar located at the outer peripheral edge of the race is lengthened using a flange, and that a radially inwardly protruding dimple is formed in an area made up of the collar and the flange, and this protruding dimple axially contains the cage.
The flange that attaches to the collar acts as a guide panel for the lubricant stream and provides for its directed exit from the bearing. The radially inwardly facing protruding dimple in turn holds the bearing unit, which includes these three components, securely together.
Advantageous developments of the invention are described in dependent claims 2 through 11.
Thus, claims 2 and 3 provide that the protruding dimple is located either in the transition area of collar and flange in a radial plane containing the associated second race or in the area of the flange.
In the first case, the first race is securely supported off of the other race, whereas in the second case an expansion of the axial bearing is made possible in case a shaft supported by it lifts up.
According to other additional features in claims 4 and 5 the protruding dimple is formed of either a number of retaining projections evenly distributed along the perimeter or is to be designed as a continuous edge.
Whereas in the first case, the open annular gap between the two races is enlarged as a result of the retaining projections at a distance from one another, thus allowing the lubricant to flow through without considerable flow resistance, in the second case the oil retention capability of the bearing is increased by the continuous edge.
According to another feature in claim 6, the protruding dimple is formed by stamping, which is a technologically very easy means of manufacture.
According to another feature in claim 7, the race is also to be continued at its inner peripheral edge by means of a flange. This second flange acts in principle similar to the first, i.e. it enables a directed influx of the lubricant into the bearing unit.
Claim 8 states that the axial dimension of the flange should correspond approximately to the dimension of the entire bearing unit. However, these size ratios can vary depending on the individual installation and can assume different values.
In a further aspect of the invention, the axial bearing unit is further held together by providing the collar located at the inner peripheral edge of the race with a protruding dimple that is directed radially outward and that axially contains the cage.
According to another feature in claim 10, the collar located at the inner peripheral edge is provided with curved recesses evenly distributed along the perimeter. This design makes the influx of the lubricant into the bearing easier since an enlarged gap between the collar of the first race and the other race is created in this way.
Finally, according to another aspect of the invention, the cage is to be profiled as seen in the longitudinal direction and has a bead at each of its inner and outer peripheral surfaces, by which the cage is held in the axial radial direction at the collars of the races.
The invention is explained in more detail in the following exemplary embodiment.